Peter john marfell



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Patented Aug. 15, 1916.

P. 1. MARFELL. I APPARATUS FOR AUTOMATICALLY BALANCING CRANES.

APPLICATION FILED SEPT 2| I9I5 I P. J. MARFELL. APPARATUS FOR AUTOMATICALLY BALANCING CRANES.

APPLICATION FILED SEPT. 2, I915.

Pat ented Aug. 15, 1916.

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UNITED STATES FATE T @FFTQE.

PETER JOHN MARFELL, OF,DUNEDII T, NEW ZEALAND.

APPARATUS FOR AUTOMATICALLY'BALA'NCING CRANES.

Specification of Letters Patent.

Application filed September 2, 1915. Serial No. 48,744.

used for raising, shifting and lowering weights of any kind, whose hftmg boom or jib overhangs its support, may be automatically balanced according to the weight raised, shifted or lowered.

The method adopted according to this invention is to use the power required to divert from a straight line any part of the hoisting rope or ropes, towhich the weight is suspended, to transmit motion to a weighted car which may be termed a balance or counter weight and move it along a track, so that the said counter weight will balance the loaded crane on-its supports.

Referring to the drawings accompanying the specification :Figure 1 is a side elevation showing the invention applied to an ordinary derrick crane. Fig; 2 is a plan view of Fig. 1. Fig. 3 is an end elevation of Fig. 1, a portion of the jib of the crane being removed. Fig. 4 is a side elevation showing the altered position of the counter weight and. t5 operating parts when a load is on the crane. Fig. 5'is a side elevation showing the altered position of the counter weight and the grade of the counter weight track due to the altered angle of the jib. Figs. 6 and 7 are, respectively, a side elevation and a plan view, on an enlarged scale, of the means shown in Figs. 1 and 2 for compensating for the varying angle between the hoisting boom and the support of the crane.

The invention is contemplated in connection with the ordinary derrick crane in which hoisting or load rope (1) which supports the load (2) is passed over a revoluble pulley (3) mounted near the rim of a revoluble grooved wheel (a) and under a pulley (5) mounted on a shaft (6), upon which said shaft (6) the grooved wheel (4:) may also be mounted; the said shaft being supported by suitable bearings secured to the jib (7 of the crane. It will be noticed that by so training the hoisting rope'l over the pulleys above mentioned the portion of the rope in passing over and under the pulleys (3) and (5) is diverted from a straight line and 1s then led to the winding drum on the derr1ck of the crane. There is a traction rope (8) having an end fixed at a suitable point on the rim of the grooved wheel 1), the said rope being adapted to lay in sald groove of the wheel. The rope 8 is led from the wheel 1 under a pulley (10) to a fairlead (10 mountedin a position near the base of the jib of the crane, and 1s then led over a pulley mounted on the outer endof the counter weight track (11) and, finally, attached to the counter weight Patented Au 15, 1916.

(12). Thecounter weight 12 is here shown as mounted on wheels or rollers and is adapted to travel back and forth along the track 11. The movement of the said counter weight is controlled by the straightening of the load rope (1) when taking the strain of the weight to be lifted. The straightenlng of the rope partially rotates the grooved wheel 1) producing a movement in the rope (8) in the direction of the arrow head (8*) and thus transmits motion to the coun ter weight moving it rearward along the track (11) to a position where it will balance the weight which is suspended by the load rope (1).

The compensation of the varying radius or angle of the hoisting boom or jib (7) relative to the support of the crane is arrangedby altering the gradient of the counter balance track (11) pivotally attached to the derrick support (11) at (11 by means of a device actuated by the movement of the said jib. One method shown in Figs. 1, 2, 6

and 7 is the provision of gearing comprising a bevel wheel (13) mounted on the pivot shaft (1 L) of the jib (7) and adapted to mesh with a pinion (15) keyed to a. shaft (16) suitably mounted on bearings, said shaft projects rearwardly in alinement with the counter weight track (11) and has on its rear end albevel pinion (17 which is adapted v to mesh with a bevel wheel (18) keyed to a shaft (19) mounted in suitable bearings bolted to the rear end of the counter weight track support (20). There is a cam (21) keyed to the shaft (19) which engages with a friction roller (22) suitably mounted to the frame work of the said counter weight track (11) the said cam being actuated by the adjustment of the jib through the me dium of the said bevel gearing and rearwardly projecting shaft raises or lowers the said track altering the grade thereof, and effecting the distance through which the counter weight travels when the crane is taking a load.

That I claim and Letters Patent is 1. A cranecomprising, in combination, a frame, a hoisting boom pivoted to the frame, a counter weight movable on the frame, an actuating member for the counter weight mounted on said hoisting boom, and a hoisting line supported from the hoisting boom and having connection with said actuating member for moving said counter Weight when a load is on said hoisting line.

2. A crane comprising, in combination, a frame, a hoisting boom pivoted to the frame, an adjustable support on the frame, a counter weight movable on said support, means for raising and lowering said boom, means for automatically varying the inclination of the support according to the position of said boom, an actuating member for the counter weight, mounted on the hoisting boom, and a hoisting line supported on said hoisting boom and having connection with said actuating member for moving said counter Weight when a load is on said hoisting line.

3. In a hoisting crane, and in combination, a hoisting line for the crane, a movable counter Weight for balancing said crane when the hoisting line is subjected to a load, and an operating member for said counter weight and having connection with said hoisting line for interrupting the straight alinement of the latter when not under a load, said operating member being actuated to operate said counter-balancing weight when the hoisting line is placed under a load.

4. The combination with a hoisting line of a hoisting crane, of a movable member supported on the crane and connected with the hoisting line, and a counter-balancing Weight for the crane having a connection with said member and normally operating said member to retain a portion of the hoisting line diverted from a straight line, said member being actuated by said hoisting desire to secure by line to move said counter-balancing weight when a load is on said hoisting line.

5. In a derrick, a supportlng frame, a holstlng boom on sald frame, a wheel oursaid wheel,

point intermediate the end of said hoisting boom and said Windlass.

6. In a derrick, a derrick frame, a hoisting boom pivoted to said frame, a counterbalancing weight for the derrick, a runway for said weight pivoted to said frame, a cam member mounted on the frame and having the cam surface thereof engaging with said runway, and gearing between said hoisting boom and cam whereby the latter is rotated by the movement of the hoisting boom to vary the inclination of the runway.

7. In a derrick, a derrick frame, a hoisting boom pivoted to said frame, a counterbalancing weight for the derrick adapted to be automatically adjusted thereon, a runway for said weight pivoted to said frame, a cam member mounted on the frame and having the cam surface thereof engaging with said runway, gearing between said hoisting boom and cam whereby the latter is rotated by the movement of the hoisting boom to vary the inclination of the runway, a wheel journaled on said hoisting boom, a Windlass on the derrick frame, a pulley mounted adjacent the periphery of said wheel, a pulley on the axis of said wheel, connecting means secured to said counter-balancing weight and to the periphery of said wheel, and a hoisting line extending over the end of said hoisting boom and adapted to be wound on said Windlass, said hoisting line passing over the pulleys of said wheel at a point intermediate the end of said hoisting boom and said Windlass, substantially as described.

In testimony whereof I have hereunto set my hand in presence of two subscribing witnesses.

PETER JOHN MARFELL. Witnesses:

EILEEN CARTER, ROBERT PARK, J r.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C. 

